Exit door lock



O t, 6, 1936, J. c. SCHAT'ZLEIN EXIT DOOR LOCK 1 2 Sheets-Sheet 1 Filed Dec. '12, 1954 0d. 6, 1936. J. c. SCHATZLEIN 2,056,537

EXI T DOOR LOCK Filed Dec. 12, 1934 "2 Sheets-Sheet 2 Emma tot Patented Get. 6, 1936 UNITED STATES PATENT OFFICE EXIT DOOR LOCK Application December 12, 1934, Serial No. 757,108

Claims.

This invention relates to locks and more par- ,ticularly to a lock adapted to be applied to double doors,.such as the exitdoors of a public building. The lock is adapted to be used in connection with 5 so-called panic bars which lie across the face of the door and are operable to retract the latch and permit the door to open In the case of doors of. this type, one of the doors is usually normally. closed and secured at the top and bottom, while the other door is provided with a locker latching mechanismwhich cooperates with a strike or strike plate upon the first or normally closed door... It is desirable, however, to have the doors arranged so thatin an emergency, or when desired, either of the doors may open or both may open simultaneously. In order that this may be done, it is necessary to out back or bevel the facing edges of the two doors so that neither will bind. against the other when 1. opened alone .or.when opened simultaneously.

. When the facing edgesiof the doors are cut back or beveled in this. manner, there is .a space left between them, which isundesirable for several reasons, one being that it .will .permit the insertion of 9 a tool to force .back the bolt and permit the door tov be opened by an unauthorized person.

. Another disadvantage of such a lock s. that the latch 'bolt zdoes not overlap the strike sufficiently to engage it in a secure manner.

30 .One object of the present invention is .to provide a lock or latching structure for a door of this character which will obviate the disadvantages above referred to.

Another object of the invention is the provision 35 of a lock mechanism for double swinging doors which will provide a movable strike or latch-engaging member upon one of the doors to engage the latch upon the other door. I

A still further object of the invention is the 40 provision of a look structure having a movable strike plate which will project beyond the edge of the door to engage thelatch bolt and thus provide for a greater area of engagement between the bolt and strike than if "the strike were flush 4.5 with the edge of the doorand casing.

To these and other .ends, the invention consists in the novel features and combinations of parts to be hereinafter described-and claimed.

In the drawings:

50 Fig. 1 is a front elevational view of a pair of double swinging doors having applied thereto a lock embodying my invention;

Fig.2 is a faceview of, the door shown as the left-hand door in Fig. 1;

55 Fig. 3 is a faceview of the right-hand door;

' doors.

Fig. 4 is a partial sectional view on line 4-4 of Fig. 1;

Fig. 5 is a sectional view on line 55 of Fig 4;

Fig. 6 is a sectional view on section lines 6-6 of Figs. 4 and 5; and

Fig.7 is a sectional view on line 1--1 of Fig. 1.

To illustrate a preferred embodiment of my invention, I have shown in Fig. 1 of the drawings a pair of swinging doors I!) and II. The door represented by the numeral lll is the one which will 10 be normally closed and is provided with a bolt casing I2 having the bolts l3 and I4 projecting upwardly and downwardly therefrom to engage the door casing at the top and bottom to hold the door in closed position. These bolts will, as 15 is usual, be operated by the panic bar 15. It will be understood that, as is the usual custom, the doors l0 and II will close against the door jamb or portion of the casing, as shown at I l in Fig.7.

. While I have shown my lock structure as being :2 applied to double swinging doors, it will be understood that it may, if desired, be employed with a single swinging door. In such case, the strike mechanism applied to the door H], as will be hereinafter described, will usually be applied to the door casing of a single door.

Upon the inside of the door I I is mounted the lock casingv l6 having a latch bolt H and a dogging plunger l8 which projects from the front edge of the lock casing and engages the strike when the door is closed, to be retracted into the lock casing and dog thelatch boltlagainst retraction .by an instrument inserted between, the edges of the Such a plunger is commonly used with doors of this type and need .not be further described. The latch bolt ll may be, and preferably is, of the swinging or pivoted type shown in the patent to W. J. Carroll, No. 1,555,829, October 6, 1925 and is designed to be operated by the panic bar 19 in the usual manner. 40 In this instance, the lock case 16 is applied to the face of the door so that the latch bolt ll engages the face of the cooperating door or a strike plate mounted upon the'face of this door. It will be noted that the facing edges'of thedoors are cut back or beveled to some extent, as shown particularly in Fig. 4, which arrangement provides against any binding action if either of the doors is opened before the other or if both are opened simultaneously. A strike plate 2!] is provided upon the face of the door I I, and a corresponding strike plate 2! provide-d on the facing edge of the door H], the latter strikeplate preferably being a part of a casing or fitting 22 mounted upon the door III, as will be hereinafter described.

It will be apparent that with the facing edges of the doors, and particularly the inner surfaces thereof, disposed as far apart as is necessary to provide free swinging movement of the doors, only a small portion of the latch bolt Il engages the edge of the door I0, and that there is a considerable space between the two doors which would provide for the insertion of a tool to tamper with the lock. Moreover, with the surfaces of the doors as far apart as is shown, the dogging plunger I8 might not be retracted to a suflicient extent to dog the latch.

In order to obviate these disadvantages, I have provided a strike plate or latch-engaging member which is movable to a projected position beyond the face of the door I 0. For this purpose the casing or fitting 22 is mounted upon the door I0 adjacent the edge thereof, the casing being provided with an opening 23 facing the lock case I6, through which opening is adapted to swing a movable strike or latch-engaging member 24. This latch-engaging member is shown in face view in Fig. 3 and in top plan view in Fig. 4 and is pivoted to the casing by the pivot rod 25, so that it may swing to the full-line position shown in Fig. 4 where it projects beyond the strike plate 2| on the face of the door Ill, or to the dottedline position shown in Fig. 4 where it is housed within the fitting or casing 22. This latch-engaging member is provided with an opening or recess 26 in its forward face to receive the latch bolt I1, and above this recess is provided with a solid portion 21 to engage the dogging plunger I8.

The coil spring 28 surrounds the pivot pin 25, the upper end of this spring bearing against the rear edge of the latch-engaging member 24, as shown at 29 in Fig. 4, and the lower end bearing against a part of the casing 22, as shown at 30 in Fig. 6. It will be apparent that this spring will normally hold the latch-engaging member 24 in its projected position, as shown in Fig. 4, and preferably this spring is made stronger than the spring projecting the latch bolt. I! and the dogging plunger l8, so that the latch bolt and plunger will be moved into the lock case I6 when they contact the member 24.

A brief description of the lock mechanism may now be helpful. As has already been explained, the strike mechanism comprising the casing or fitting 22 and its contained parts is mounted upon the door I!) which is normally closed and held in closed position by the bolts l3 and I4, and the door I I will be the door which is normally employed for exit .and entrance. This, however, is only a matter of choice, as either door may be used particularly for exit, as either may be opened by the operation of its panic bar I5 or II]. It will be understood that the normal position of the latch-engaging member 24 is its projected position, as shown in full lines in Fig. 4, whether this door is open or closed, and that ordinarily this latch-engaging member will only be moved to its retracted position within the casing 22 when the door I0 is opened before the door II.

If the door I0 is closed and the door I I is closed thereafter, the latch bolt I! and plunger I8 will strike against the latch-engaging member 24 and both will be moved into the casing I6. When the door I I has been closed to a suflicient extent for the latch bolt to move opposite the opening 26, however, this bolt will spring outwardly into this opening and its rear edge will engage with the rear edge 3| of this opening, thus securely latching the door in closed position. The dogging plunger will be retained in its retracted position by engagement with the solid portion 21 of the movable strike or latch-engaging member 24. The doors are now in the position shown in Fig. 4. It will be noted that the engagement of the rear edge of the latch IT with the surface 3| will prevent the latch-engaging member 24 from being rocked about its pivot to retracted position by a tool inserted between the doors, so that it would be difficult for an unauthorized person to open the door by such means from the outside. If a tool were to be inserted between the doors, as

shown in Fig. 4, and pressure applied thereby to the member 24 to rotate it about its pivot, this pressure would be resisted by the latch bolt I'I due to the engagement of its flat side with the surface 3|. This pressure would not tend to retract the latch bolt I! but would merely press inwardly the door I I upon which the latch bolt is mounted. As the door is already against the jamb, it will be apparent that the bolt-engaging member 24 would not be permitted to move, and hence the doors could not be forced in this manner.

The door II may, of course, be opened in the usual manner by operation of the panic bar I9 to retract the latch bolt N. If, however, both doors are opened simultaneously, or if the door III is opened first by depression of its panic bar I5, the latch-engaging member 24 will contact with the strike plate 20 and be retracted within the casing 22 so that there will be no tendency of the doors to bind, and either may be opened before the other or both may be opened simultane ously. It will also be apparent that there is a secure engagement between the movable strikeengaging member 24 and the latch bolt I! to securely hold the door I I in closed position. The edges of the doors are, as stated, sufiiciently beveled so that they will not foul each other regardless of which door may be opened first or in case they are opened simultaneously.

While I have shown and described a preferred embodiment of my invention, it will be understood that it is not to be limited to all of the details shown, but is capable of modification and variation within the spirit of the invention and within the scope of the appended claims.

What I claim is:

1. In a latch mechanism for double doors having their face edges in spaced relation when closed, a casing secured to one door adjacent the edge thereof and having a latch bolt adapted to project therefrom, a strike mechanism secured to the opposing edge of the other door, a latch bolt engaging member movably secured to the strike mechanism and adapted to project into the space between the doors to there engage the latch bolt when the doors are closed, spring means constantly urging said member to projecting position, and said member being movable to a retracted position by contact with the face of the door upon which the latch bolt is mounted.

2. In a latch mechanism for double doors, a casing secured to one door adjacent the edge thereof and having a latch bolt adapted to project therefrom, a strike mechanism secured to the opposing edge of the other door, a latch bolt engaging member movably secured to the strike mechanism and adapted to project into the space between the doors to engage the latch bolt, and spring means constantly urging said member to projecting position, said member being freely movable toward retracted position when the door upon which it is mounted is opened.

3. In a latch mechanism for double doors a casing secured to one door adjacent the edge thereof and having a latch bolt adapted to project therefrom, a strike mechanism secured to the opposing edge of the other door, a latch bolt engaging member m'ovably secured to said strike mechanism and spring-pressed toward a projecting position into the space between the doors to engage the latch bolt, and said member being movable to a retracted protracted position by contact with the face of the door upon which the latch bolt is mounted.

4. In a latch mechanism for double doors, a casing applied to the edge of one door and having a retractible latch bolt projecting therefrom, a latch bolt engaging member movably mounted adjacent the edge of the second door and projecting into the space between the doors to there engage said latch bolt when the doors are in closed position, and said member being movable toward non-projecting position by contact with the first door when said doors are opened simultaneously or when said second door is opened before said first door, and a spring constantly urging said member to projecting position.

5. In a latch mechanism for double doors adapted to close against a door jamb, a casing secured to one of the doors and having a latch bolt apated to project therefrom, a strike mechanism mounted upon the other of said doors to cooperate with the latch bolt, said strike mechanism having a movable latch-bolt-engaging member adapted to be projected beyond the face of the door upon which it is mounted into the space between the two doors to there engage the latch bolt, means for urging said member to projecting position, said member having a flat surface engaging the back of the latch bolt and being held against movement to retracted position by engagement with the latch bolt when the doors are in closed position and said first door is against the door jamb.

JAMES C. SCHATZLEIN.

CERTIFICATE OF CORRECTION.

Patent No. 2,056,557. October 6, 1956.

JAMES C. SCHATZLEIN.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5, first column, line 10, claim 3, strike out the word "protracted"; and second col umn, line 8, claim 5, for "epeted" read adapted; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 8th day of December, A. D. 1936.

Henry Van Arsdale (Seal) Acting Commissioner of Patents. 

